Grinding mill



Jan. 28, 1930. A. J. HAZLE, JR I 4 GRINDING MILL Filed March 19, 1926 1 19 Patented Jan. 28, 1930 UNITED STATES ALBERT J. HAZLE, JR., OF CHICAGO, ILLINOIS, ASSIGNOR TO BLATCHFORD CALF MEAL PATENT OFFICE COMPANY, OF \VAUKEGAN, ILLINOIS GRINDING MILL Application filed March 19, 1926. Serial No. 95,879.

This invention relates to mills adapted for grinding various materials but which are particularly intended for grinding grain or the like. Mills of this character which are provided with centrifugal heaters are usually run at very high speeds and it requires a large amount of power to start such mills. In other words, the power required for bringing a mill from stationary position up to running speed is very much greater than the power required for the normal operation of the mill. It is also desirable to change the screens in such mills when different grains or materials are to be ground, and in order to avoid waste of power, it is desirable to provide means for changing such screens without stopping the mill.

I have found that it is desirable to provide means for adjusting the screens toward or away from the heaters in order to facilitate the grinding operations for different kinds of grain. Accordingly, the present invention is particularly directed to. the screen arrangement for centrifugal mills.

The objects of this invention are to provide an improved centrifugal grinding mill hav ing an adjustable screen; to provide an improved grinding mill with a screen which may be removed or replaced, and which may also be adjusted with respect to the heaters while the mill is in operation; and to provide such other advantages and improvements in construction as will be described more fully hereinafter.

In the accompanying drawings illustrating this invention:

Figure l is a longitudinal, sectional view of a mill embodying my improved construction; and

Figure 2 is a detail plan view taken on the line 2-2 of Figure 1.

The mill as shown in these drawings, has a rectangular base 3 with end walls 4: and side walls 5. The main shaft 6 is mounted in the base and carries the heaters 7. The cover or top portion 8 is secured to the base in any convenient manner and is preferably provided with stationary grinding members which cooperate with the heaters. The end walls 4 of the base are provided with a pluthe shaft 6 in order to hold the screen in proper relation to the heaters, but project outwardly at the front of the machine so that the screen may be inserted and removed through a longitudinal slot or opening 11. The upper edge of the screen or perforated plate may project into such slot a sufficient distance so that it may be readily engaged by pliers or the like for convenience in removing the same. This opening has a cover plate 12 which is held by screws or bolts 13. While any suitable sort of screen may be used, I prefer to use perforated sheet metal which may be readily introduced into the slot and which has sufficient flexibility so that it may be pushed into position through the opening 11. By means of this arrangement, it will be readily seen that these screens may be adjusted, or removed and replaced with other screens, without stopping the mill and will thereby greatly increase the efficiency and usefulness of the mill.

It will be noted that the mill may be made in various sizes and changes may be made in the details of construction in order to adapt it for different purposes and therefore I do not wish to be limited to the particular construction shown and described, except as specified in the following claims, in which I claim 1. A centrifugal mill having a plurality of slots for receiving a screen whereby the screen may be adjusted toward and away from the heaters.

2. A grinding mill having two or more substantially semi-circular slots of different radii for receiving a screen, a screen adapted to engage with said slots, said slots opening to the outside of the mill whereby the screen may be removed and replaced while the mill is in operation.

3. A grinding mill having a base with" a plurality of slots which are substantially concentric with the axis, a screen adapted to engage with different slots to adjust it toward or away from the axis, said mill having a longitudinal opening through which the screen may be inserted and withdrawn, and a cover plate for said opening.

4. In a grinding mill, the combination of a base, a shaft mounted in said base, beaters carried by said shaft, :1 cover comprising the upper portion of the mill, said base having a plurality of substantially semi-circular slots in each end thereof, a screen adapted to be inserted in different pairs of said slots for adjusting-its position toward or away from the axis, said base having a longitudinal opening in one side thereof through which the screen may be inserted and withdrawn, and means for covering said opening.

5. A centrifugal grinding mill having a casing provided with a plurality of substantially semi-circular slots in each end thereof for holding a screen in different positions radially with respect to the grinding members.

ALBERT J. HAZLE, JR. 

